Prepare to remove StartRtcEventLog and StopRtcEventLog

There are some internal projects that need to be updated before we remove StartRtcEventLog and StopRtcEventLog. In this CL we take away the pure-virtuality status of the functions. After landing this, we can fix the internal projects, then land https://webrtc-review.googlesource.com/c/src/+/6782.

TBR=stefan@webrtc.org

Bug: webrtc:8111
Change-Id: Ibe495a7e7d6bf8120b1a26f056bd1443031733bf
Reviewed-on: https://webrtc-review.googlesource.com/6980
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20178}
diff --git a/api/peerconnectioninterface.h b/api/peerconnectioninterface.h
index da88e39..c138e9e 100644
--- a/api/peerconnectioninterface.h
+++ b/api/peerconnectioninterface.h
@@ -1032,16 +1032,20 @@
   // use the equivalent function on PeerConnectionInterface.
   // TODO(ivoc) Remove after Chrome is updated.
   virtual bool StartRtcEventLog(rtc::PlatformFile file,
-                                int64_t max_size_bytes) = 0;
+                                int64_t max_size_bytes) {
+    return false;
+  }
   // This function is deprecated and will be removed when Chrome is updated to
   // use the equivalent function on PeerConnectionInterface.
   // TODO(ivoc) Remove after Chrome is updated.
-  virtual bool StartRtcEventLog(rtc::PlatformFile file) = 0;
+  virtual bool StartRtcEventLog(rtc::PlatformFile file) {
+    return false;
+  }
 
   // This function is deprecated and will be removed when Chrome is updated to
   // use the equivalent function on PeerConnectionInterface.
   // TODO(ivoc) Remove after Chrome is updated.
-  virtual void StopRtcEventLog() = 0;
+  virtual void StopRtcEventLog() {}
 
  protected:
   // Dtor and ctor protected as objects shouldn't be created or deleted via